LOS ANGELES -- The creators of Amazon's "Catastrophe," which stars Carrie Fisher in one of her final roles, said they were shocked by her unexpected death last year and had bigger plans for her character.

"We had no idea. I don't think she had any idea," series star and co-creator Rob Delaney said in an interview Thursday.

On Dec. 23, Fisher was returning to Los Angeles from London after shooting her final scenes for season three of "Catastrophe." She suffered a medical emergency aboard the flight and died on Dec. 27 at Ronald Reagan UCLA Medical Center.

Fisher, 60, played Delaney's mother, Mia, in the series about a couple navigating the highs and lows of marriage and parenthood. The new season begins streaming April 28.

The show also stars Sharon Horgan, who spent time with Fisher the night before her fateful flight.

"We had dinner and she skipped off to her room," said Horgan, who is also a "Catastrophe" co-creator. "And she had been at the antique market earlier that day and she was showing me all these lovely little bits and pieces that she bought for her mom to bring back."

Fisher's mother, actress Debbie Reynolds, died the day after her daughter. Reynolds was 84.

Horgan said Fisher spoke of a renewed excitement about her acting career and "had massive plans to do more of that."

"She brought her incredible, crazy, hilarious, warm, kind personality, but she also brought us the character of Mia. You know, we wrote it down, but she made her the brilliant monster that she is," Horgan said. "I miss her, but I'll miss her in our show, you know, I'll miss that character and I'll miss being able to tell that character's story."

Delaney and Horgan said they deeply regret not having more time with the actress and her "Catastrophe" character.

"Only now am I realizing -- because I've been sad as a human being and friend of hers -- but yeah, I do feel now stolen from," Delaney said.

"We wanted to do a lot more with Carrie. I was only just beginning to be invited to her house!" Horgan said. "We wanted to tell more about that character. We wanted to flesh her out more and give her a story and a reason for her behaviour. And the only reason why we did that is because Carrie made us want to do that."